Flocks of monarch butterflies regularly migrate across North America to overwinter in Mexico, a natural phenomenon considered “one of nature’s epic journeys.” But the numbers of insects making the more than 4,500-kilometer trip has declined steeply in recent years.

Citizens, preservation organizations and governments are joining forces to help the delicate and colorful creatures migrate. The plan is to increase the availability of a specific plant at hundreds of places on the flight route.

The native milkweed is the only thing the monarch caterpillar eats, and the plant is critical to the monarch’s reproduction. But this weed has become scarcer as farmers have become more efficient at keeping it out of their crops.

Children don monarch butterfly costumes at a wildlife refuge in Texas. (USFWS)

“Working with partners, we will restore and enhance more than 200,000 acres [81,000 hectares] of habitat for monarchs on public lands,” wrote Director Daniel Ashe of the U.S. Fish and Wildlife Service (USFWS) in a recent agency publication.

USFWS also supports projects to create habitats for butterflies and other pollinators in 750 schoolyards nationwide. The government has a private-sector partner in the Monarch Joint Venture, a coalition dedicated to protecting and restoring monarch populations.

Monarch-saving has more supporters in Mexico. In 1996, the Mexican government created the Monarch Butterfly Biosphere Reserve to protect the butterfly’s wintering habitat. Mexican government and private conservation groups work with local communities to better manage natural resources to sustain the insect population.

Monarchs cluster together in trees during winter. (USFWS)

About 20 years ago, the monarch population spending the winter in Mexico was thought to be more than 1 billion butterflies. Forests would become curtains of orange and black as the insects clustered in the trees. Research teams calculate that the 2014 population is only 6 percent of its former number.